Products for impact testing

Pendulum and drop weight impact testers

Impact testing has become firmly established in materials and components testing. The characteristics determined are part of basic material characterization. Zwick Roell has been delivering quality testing systems for impact testing for years. Its product line includes pendulum impact testers for metals and plastics, drop weight testers with an energy range of only a few joules to 100,000 joules, as well as high-speed testing machines.

Impact Tests on Plastics and Metals

With Zwick, your tests are always in compliance with the standard!

Impact tests are short-term tests which provide information on the failure behavior of materials or components subjected to rapid loading and at varying temperatures. All materials are used on a daily basis with fluctuating temperatures. Since the fracture behavior depends on the temperature, materials are often tested in the entire operating temperature range, indicating at which temperature and to what extent a material becomes brittle under temperature.

Non-instrumented plastics testing

There are ISO product, method, and instrument standards for impact tests with pendulum impact testers.

Product and method standards describe how specimens are taken from a variety of materials and tested. Alternatively they describe a test method for a product or material group.

Instrument standards describe how test instruments are designed. They specify the technical data and their tolerances and define how testing instruments should be verified.

While our customers mainly rely on product standards, as a manufacturer of instruments Zwick is bound by both product standards (for the test sequence) and instrument standards (for the technical design of the test instrument). Both groups of standards are therefore listed below.

As a rule, ASTM standards do not differentiate between product, method, or instrument standards.

Instrumented tests on plastics

The following characteristics are determined in instrumented Charpy tests to ISO 179-2:

Maximum force

deflection at maximum force

energy up to maximum force

deflection at break

energy at break

Non-instrumented metals testing

For impact tests on metals ASTM E23 permits a speed which can also be complied with using the HIT 25P or HIT 50P. Special accessories are required - see Section 14.3.5.

Type of test

Product/method standard

Initial potential energy[J]

Speed[m/s]

Lower measurement limit in %of nominal initial potential energy

Upper measurement limit in %of nominal initial potential energy

Instrument standard

Lower measurement limit in %of nominal initial potential energy

Upper measurement limit in %of nominal initial potential energy

Initial potential energy[J]

Speed [m/s]

Charpy

ISO 148-1

n.s.

5 to 5.5

n.s.

80 %

ISO 148-2JIS B 7722

n.s.

80 %

5 to 5.5

n.s.

EN 2003-1

300 (others are permitted)

5 to 5.5

n.s.

n.s.

EN 2003-3Ident.BS 131-4 1972

n.s.

n.s.

5 to 5.5

n.s.

ASTM E23

n.s.

3 to 6

n.s.

80%[1]

none

ASTM E436

>2700

>4.88

n.s.

n.s.

none

old standard DIN 50115

≤ 5.5>5.5 ... 50>50 ... 750

2.8 to 3.13.6 to 45 to 5.5

n.s.

80 %

ISO 148-2JIS B 7722

n.s.

80 %

5 to 5.5

n.s.

Izod

EN 2003-2

n.s.

3.5 ± 0.5

n.s.

n.s.

EN 2003-3ident.BS 131-4 1972

n.s.

n.s.

3 to 4

n.s.

ASTM E23

n.s.

3 to 6

n.s.

80 %

none

Measured values can be valid in some cases even if limit is exceeded

n.s. = not specified

Instrumented metals testing

Type of test

Product/method standard

F range[kN]

Speed[m/s]

Measurement uncertaintyForce [% Fact]

Transfer frequencymin. [kHz]

Instrument standard

Lower measurement limit

Upper measurement limit in %Of the rated initial potential energy

Potential energy[J]

Speed[m/s]

Charpy

ISO 14556

1 (for Fa)to40 (for Fm)

5 to 5.5

1%In the F range10 to 100 %Recommended for tups only

100Increase time: 3.5 µs)

EN 10045-2ISO 148-2JIS B 7722

n.s.

80 %

n.s.

5 to 5.5

n.s. = not specified

Impact tests on elastomers and foam

The objective of tests on elastomers and foams is the straightforward and fast measurement of material elasticity.

One material that is up to 100% elastic stores supplied energy and releases it at the moment the force is no longer applied. In contrast, material that is up to 100% plastic absorbs supplied energy completely.

These characteristics are used to measure rebound resilience:

A disk-shaped specimen is clamped to a massive block. A pendulum hits the specimen and supplies energy through the hit. The elastic part of the specimen saves the energy (the pendulum rests for a moment) and then returns the energy to the pendulum. The pendulum is accelerated in the opposite direction and swings back.

Once it reaches its resting position after returning, the backward swing angle is measured. Using the angle, the elastic energy that the specimen returned to the pendulum is calculated.